Chip grafting also known as Chip budding is a fairly easy grafting method to master. Instead of grafting an entire shoot onto a root stock, just a single bud is grafted on.Not only is it relatively simple it is highly efficient.
With chip budding, a bud on a chip of the trees wood [with bark] is inserted into a compatible notch on the host – the root stock. Chip grafting is carried out in late summer and early autumn.
Before proceeding, you will need a suitable root stock to graft into. Rootstocks can be purchased from rootstock growers or they can be raised from seed or cuttings. The rootstock must be a related tree indigenous to the area in which it is planted. Not that I’m comparing apples to oranges, but you can’t graft an orange onto an apple tree. You can however graft a pear onto an apple tree, a lemon onto an orange tree and a stone fruit such as a peach onto a plum tree and vice versa.
The highest success rate is with trees grafted to their own kind, such as one variety of apple onto another. The most interesting results however, although not as easy to attain is grafting various cultivars of related fruits together.
One creative botanical artist produced a fruit tree with 40 different stone fruits on the same tree – See : Fruit Salad Trees. Syracuse University art professor Sam Van Akens tree is comprised of 40 different branches from various stone fruits. Plums, Peaches, Apricots, Cherries, Nectarines and even almonds of assorted cultivars all grafted together.
Come mid-summer choose the buds you plan to chip graft. They should be from well-ripened, current season’s growth, non-flowering shoots that are comparable in diameter to the rootstock. These are known as budsticks.
Remove the lower shoots and foliage from the root stock, lower meaning anything within a foot of the ground.
Securing a “budstick” From the donor tree, the tree from which you are removing the bud. Using a sterilized sharp knife make your first cut 3/4 inch wide X 1/4 inch deep cut in the root stock below the bud you wish to remove. The cut should be at roughly a 30 degree angle . Make your second cut roughly an inch and a half above the first, with the bud you are harvesting cenetered between the 2 cuts. Cut down and around the bud to join the two cuts. Take care not to damage the bark any more than is absolutely necessary. From the budstick gently cut off any new tender tip growth, just don’t get carried away. Remove any excess leaves.
Next – make more 2 cuts, in the root stock this time, that you will merge together in much the same fashion as described above. Thess two cuts that become one should be roughly 5-6 inches above the ground. The shape and dimensions must match that of the first cut, be sure to leave the bark on this sliver intact.
Insert the budstick into the budchip and then into the ‘lip’ of the cut out of the rootstock. It is vital that the cambium layers match as closely as possible. Fasten the joint together with grafting tape or even plastic will suffice. Leave the bud exposed, do not cover it with grafting tape or plastic.
Do not remove the binding until the bud begins to swell. This process is best done on tree that have not yet been planted out, but can be done on trees that are already in the ground at a lower success rate. Don’t get discouraged if your first graft doesn’t take – it happens to even seasoned pros. Practice before going “live” practice makes perfect.
The most common reason for failure of buds to take is from not matching the cambium layers up accurately enough. Practice on spare shoots to achieve a good match up of the cambium. You may also want to graft several buds in anticipation that at least one will take, just don’t get carried away and do extensive damage to the root stock.